Post navigation

28 thoughts on “After Earth”

Sometimes I try to figure out what you could do with a heavy lift vehicle that would actually be valuable to the economic development of space.. I’ve never succeeded when I limit myself to the kind of super expensive HLV that NASA is likely to (fail trying to) build. I’ve almost gotten close thinking about space solar power with a $300M/launch for 130t to LEO (the SpaceX option) and some affordable human or robotic on-orbit assembly. It still doesn’t close, but it’s close.

Then there’s the Sea Dragon option, and you can imagine building a very reduced Island One. The real estate economics close, I think, but only if you don’t have to pay for the development of the launch vehicle. I know that’s not saying much.

The first thing we do is drop our troops like meteors in the new planets ocean. Then we send them ashore blasting everything in site. Drones will provide air cover and destroy any military installations. Then we take their water…

Hmm – the problem with the resource argument is this: If you have enough energy to be launching tons of matter into space for a colony mission (equipment mass, and people), then you have enough energy to provide for the material needs of the Earth.

The same technology that will allow you to pry the oxygen off the rocks in space and derive resources from undifferentiated oxides will allow you to provide any element on the periodic table in arbitrary quantities to the people of Earth.

The technology to allow interstellar travel implies that you have enough energy available to boil all the oceans of the world off.

In summary – resource pressures won’t be a motivation to colonize space. If we have resource pressures, we don’t have the ability to colonize. If we have the ability to colonize, we don’t have any resource concerns.

There are other troubling paradoxes involving space colonization: Assume you live in a country that you would want to get away from enough to pay for passage to a space colony – such a country isn’t about to let you leave, and economic conditions would be such that it wouldn’t have any colonies or launch capabilities available to you anyway.

Any country with the ability to colonize space is also likely to be providing for it’s own citizens well enough that they wouldn’t want to permanently leave civilization for an unfinished frontier.

Sea Dragon’s development costs could be spread out to several colonies, if that helps. I (for instance) will need to get people to Venus somehow, and I always figured that Sea Dragon would be “the 747 to LEO”. Barring a breakthrough like large-scale laser launch or Mach propulsion.

—

“The technology to allow interstellar travel implies that you have enough energy available to boil all the oceans of the world off.”

Or it implies the civilization has found a way to “cheat”, like a Warp drive or some such. I sort of assume that extra-solar travel will be off limits to physical humans until we do. Without Warp drive I think colonization on the galaxy will done “on the cheap” by sending a micro-ship with a cargo of DNA samples (to be born/cloned at the other end) and some brain uploads saved to local storage.

—

Can I just add that I hate Mars as a colony destination? It’s a gut feeling, but I don’t think that gravity will be close enough to Earth normal to support the proper growth, development and health of lifeforms adapted to 1 g. No one really knows what the safe range is, but only Venus and the outer gas giants are even ballpark similar.

People are focused on the wrong level of economics regarding space. They look for some product to export to earth which doesn’t exist. Others point out that it doesn’t exist but fail to understand why it isn’t required. Others want to sell half a planet for $10 an acre to finance some grand plan (when the land is paradoxically both worthless and worth a considerable amount more; which I can explain.) Still others say, we need $100/kg to LEO before anything can happen, but what if that never happens?

The reality is that there is nothing preventing us from moving forward today with the the technology and cost structure ($3k/kg) that already exists.

Are we seriously talking about creating a space faring, colonizing technology, BEFORE we can even find the will to got to Mars? Mars? Did I say Mars?

OUR federal goons won’t lead, follow, or get out of the way on getting back to the MOON!

And given, earthquakes, tsunamis and the inevitable big ass rock falling out of the heavens destroying all but perhaps a few people in that Two Billion Year time frame, that seems like a long, long, too long a time to be looking at.

“ams, that’s nonsense.. the US provides for vast numbers of malcontents with the resources to leave it any time they want.. some of them even do.”

I suppose that’s true. My second point is weaker than my first – perhaps desire to emigrate can drive colonization. The economic barriers to launching colony equipment then need to be lowered until they are within reach of the malcontents. Right now, setting up even the most modest lunar base might barely be within the reach of billionaires – that has to change.

PS – I’m not saying this because I am anti-space. Far from it, I’m an astro engineer, and my fondest hope is that some-day the stuff I am working on will help in the effort to expand mankind into space. I hope we do develop the technology to pry resources out of the bare rock of planets and asteroids, and also use the same here on Earth to put the final nails into Malthus’s coffin.

I’m just trying to bracket what sort of motives and economic conditions you would need to have to colonize. Going after asteroid metals because earth doesn’t have any of its own isn’t realistic as an economic driver. Leaving for space colonies because your home country is a dystopia also isn’t realistic.

ams, the best analog is the settling of the New World by Europeans (and particularly the British). Emigrants were not only allowed to leave, but the malcontents were encouraged to. It’s just a matter of technology level and economics.

In my stories, I put the colony worlds “in the same solar system as Earth” via wormhole links. These come in two types: naturally-occurring (which are called “straits”) and man-made (“canals”). Linking system to system this way allows me to use ordinary, extrapolatable interplanetary spacecraft for inter-colony travel, and cuts travel times to earth-transoceanic scale. It also eliminates pesky causality problems; since clocks at each end of a wormhole must agree (less speed-of-light lag between gates in the same system), a single timeframe exists in-story, which is what you want.

Then there’s the superplanetary sphere idea: roof over Jupiter, Saturn, Uranus and Neptune individually at each planet’s one-gee radius (using matter from the superfluous upper atmosphere of each for construction materials and energy). Pow, the Solar System now has four new super-Earths, each with a habitable surface many multiple times that of the ol’ dirtball. You have to figure out some sort of dodge to get the insolation and climate to work right, but that’s what handwaving is for.

By postulating a solar system with inhabited superplanetary worlds, you can have “interstellar” fun without the hassle of coming up with interstellar travel. You can also have fun, Golden-Age-like races — Jovians, Saturnians, etc. And if you fiddle the plot a bit, you can have these races be unaware that their homeworlds are artificial, too…

My guess: Putting all humanity in One Big Solar System via wormholes is the only way it will work in Real Life. But I could be wrong.

“I’m just trying to bracket what sort of motives and economic conditions you would need to have to colonize.”

Technology and time scales that makes it possible; profit margin that makes it worth the risk. The only reason for colonizing is if you need on site, 24/7 infrastructure.

For example, in the early 1600’s, where I live (fishing village on Massachusetts coast), the place was lousy with codfish. Huge codfish. Codfish you could dry and ship back to Europe. So much untouched codfish that it was easier to get it from here and ship it back than it was to catch it over there in the partly fished out beds. So for decades, European fisherman would sail over just prior to the start of the season (when there was a reasonable chance of getting here alive), fish, dry the fish and then, at the end of the season, sail the catch back home. Big money. They lived in shacks or leanto’s on the beach, which were swept away by Winter storms. Left essentially no infrastructure here. It wasn’t until a few decades later that people actually decided to stay (and the rumor is that the reason was because the settlers wanted to drink on Sunday).

The amount we consume each year already far outstrips what our planet can sustain, and the World Wildlife Fund estimates that by 2030 we will be consuming two planets’ worth of natural resources annually.

This is a myth that for some reason continually gets repeated. Excepting E=mc^2, which is negligible in this case, mass on Earth is conserved (I think the Earth actually accretes significant mass from space), resources can not be destroyed. This is not to say that the Earth does not have space, energy or material limits – although we are no where near the carrying capacity of Earth. Nor are there significant issues with transporting large quantities of Earth resources into space – reduced sea levels would I suspect actually increase the carrying capacity of Earth.

Financially, if not technologically, it is impossible to launch the amount of materials from Earth that one would need to build a large orbiting structure.

Actually this is wrong, the fundamental cost limit for launching mass to LEO is on the order of $25/kg (based on energy, plus dry mass cost for a high flight rate reusable launch vehicle). kilogram for kilogram it is theoretically possible to build and launch orbital habitats for around the cost of a mobile home. An orbital habitat, launched from Earth, can cost similarly to a comparable sized house on Earth (especially if land costs are included). Carbon fiber can actually be very cheap and it can make very large light weight habitats in space…

The space shuttle flew at around $450 million a trip, and today sending unmanned payloads into orbit will still set you back about $12,000 a pound, with much of the cost coming from the fuel burned in those first hundred miles.

Raw propellant cost per kilogram of payload to LEO is actually around $10/kg for LH2 or kerosene and closer to $5/kg for LNG.

In 2000, NASA’s Institute for Advanced Concepts gave Brad Edwards, founder of the company Carbon Designs, $570,000 to investigate how to construct such a device, and he estimates that he could build one for no more than $14 billion—once someone develops the nanotechnology necessary to fabricate the very thin, very strong tubes that would make up the line.

Using materials many times stronger than currently exist… And if such materials did exists launch vehicles would also become many times easier with dry mass greatly reduced. Space payload to dry mass ratio of a space elevator will always be many times that of a rocket vehicle – they will always be far more expensive than a rocket vehicle (with ~5km/s maglev climbers they get more interesting – but the added weight of this…). Rotavators, in contrast, are very economically interesting though.

An interesting point is that the amount of energy a person uses in a year is enough to get them to LEO. One does not have to be in space for too many years (adding baggage costs) before the net energy used on Earth actually reduces – space can be good for the environment. I am one of those who support the idea of moving humanity to space and turning Earth into a nature reserve – it looks viable/sensible.

Using materials many times stronger than currently exist… And if such materials did exists launch vehicles would also become many times easier with dry mass greatly reduced.

The technique needed to spin Carbon nanotubes into a 100 thousand kilometer ribbon a meter wide does not yet exist, but the material itself exists. Last time I checked (a few years ago) the fibers being produced were following a Moore’s Law of their own, doubling in length every year or so, and IIRC they were up to 10 cm back then. And the advances in materials science has been wholeheartedly embraced by the commercial space community – that’s where Scaled Composites got its name.

I am one of those who support the idea of moving humanity to space and turning Earth into a nature reserve – it looks viable/sensible.

I can’t see the entire Earth ever being completely abandoned by humanity unless it becomes uninhabitable.

Before we can go to another star we need to learn how to live around this one and we shouldn’t be wasting the most valuable thing any of us possess: time.

BEFORE we can even find the will

Our nation could do it, but the encouraging thing is, it’s almost affordable privately. I believe it can be done with a $1b/yr commitment for about ten years after a $4b startup (but more is definitely better.)

Say $20b total to give them a good fighting chance.

Research phase: Total life support provided by $1b/yr. (every 26 mo.)

12 go to mars for $4b in two ships. First priority ISRU water.

With water replacing 75% of life support needs now…

36 go to mars for $2.5b in one ship: 48 researcher on mars with total life support for $1b/yr.

They’re priority is ISRU farming (habitat ISRU is a minor research issue that is derived from ISRU farming.)

Phase two: immigration

A land claims registry is setup on mars with rules everybody agrees to (those that don’t, don’t matter, these rules apply to those that accept them whether others recognize them or not. Possession is nine/tenths.) This allows immigrants (the first million anyway) to recover whatever the complete cost of getting to mars is and provides an income to martians so they can purchase supplies from earth because they aren’t going to be in any position to export anything (if ever) for centuries. It works thusly…

Any martian can make a claim in the registry for one sq. km. (only one claim per person at a time.) This gives them 100 hectare plots to develop and resell.

A plot will have a habitat and up to 3 Zubrin 50m farms (each feeds 3 each.) Each farm allows 2 more immigrants. Developing all 100 plots (which they are not obligated to do) would take from 20 to 40 man-years providing full time work and income for life just from one claim and they can make other claims after the first.

The sales prices will include cost and 1% of their own travel cost to mars so 100% can be paid off from just the first claim.

Whatever it costs for a person to get to mars, for 1% more they can have a home waiting for them when they get to the surface. This is a deal most will take. They can also make a claim and do the same thing.

The first one million colonists can totally pay the expense of getting to mars this way.

Total cost to visionary: $20b. which is within our reach now and doesn’t require anything we don’t already have except a mars lander (accent vehicle optional.)

Actually, home sweet home will add more than 1% (but hopefully less than 5%) to the ticket price unless prices depress (which they will have pressure not to much.) For this to work they can’t be importing farms and habitat, it must be ISRU (but you’ve got 48 on mars and billions on earth to figure it out.)

I think Mars will do, barely, with regard to its gravity field. I know the data and anecdotal evidence can be read almost both ways, but our time in space since 1961 seems, to me, to show that the human body is more robust than we give it credit for.

I think interstellar colonization will only occur via the nanao-bot, upload method. Actual, realistic interstellar travel ala Avatar might work, but will never be cost-effective. So long as terraforming Mars (or developing Homo Sapiens Martensis in a lab) is cheaper than building interstellar ships, extra-solar system colonization won’t make sense.

A passenger capsule climbing this elevator will still need a rather sizeable rocket system, in case the capsule falls off the elevator. For a certain altitude range, the capsule will fall back into the atmosphere, and hit it fast enough and steep enough that the deceleration will kill the passengers. The capsule either brakes propulsively before hitting, or thrusts sideways so it enters at a shallow angle (or not at all). IIRC, the required delta V is > 4 km/s in the worst case.

The article didn’t mention Obamanomics as a motivator for space colonization. Flight to the galactic suburbs!

The first thing we do is drop our troops like meteors in the new planets ocean. Then we send them ashore blasting everything in site. Drones will provide air cover and destroy any military installations. Then we take their water…

Bah. Colonising Mars will take decades to centuries and cost trillions – at least with the technology of today or the near future. And we will still be stuck with a world with half the gravity of Earth – which will make it difficult to impossible for the two branches of humanity to mix. And it will take major space infrastructure to do, probably – Mars probably has nowhere near enough water, so we would need to land comets on it.

Space colonisation will be far faster, cheaper and can be done with less tech development. The apparently best route would involve a functioning Moon base – but that doesn’t have to be any more comfortable than an oil rig. People will be sent to the Moon for short contracts, very well paid.